10-11-2016 6:35 PM
Use this link and put "someone is using my account" into the topic bar - follow the instructions to secure your account:-
http://ocs.ebay.co.uk/ws/eBayISAPI.dll?CustomerSupport
Then run a full system scan to clear out any malware picked up from dodgy sites, emails, texts or by using an insecure internet connection. Then beef up your internet security. Then reset each and every one of your passwords and make them extremely difficult to guess. Don't forget to alert Paypal/your bank etc.
Once everything is ok, go through both your eBay and Paypal accounts and make sure that there is no rogue information in there.